como faço vaiar a array.(linha - 22)

procedure TForm1.FormCreate(Sender: TObject);
begin
a[1]:=0;a[2]:=1;a[3]:=2;a[4]:=3;a[5]:=4;
a[6]:=5;a[7]:=6;a[8]:=7;a[9]:=8;a[10]:=9;a[11]:=10;
b[1]:=0;b[2]:=1;b[3]:=2;b[4]:=3;b[5]:=4;
b[6]:=5;b[7]:=6;b[8]:=7;b[9]:=8;b[10]:=9;b[11]:=10;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
x,y,z,r :integer;
begin
for x:=1 to 11 do
begin
memo1.Lines.Add(inttostr(a[x]));
end;
for y:=11 downto 1 do
begin
memo2.Lines.Add(inttostr(b[y]));
end;
for z:=1 to 11 do
begin
22- c[z]:=a[x] xor b[y];
end;
for r:=1 to 11 do
begin
memo3.Lines.Add(inttostr(c[z]));
end;
end;